1. Technical Field
The invention disclosed broadly relates to data processing systems and methods and more particularly relates to the resolution of diverse font definitions for the printing or display of stored document text.
2. Background Information
FONTs are used to print or display character data using a combination of metrics (size and positioning data) and raster patterns (shape and density of blackness). Each specific FONT is uniquely defined by a specific combination of a Code Page and a Character Set. A Code Page equates specific characters (hexadecimal values) to unique Character Identifications. A Character Set equates those same Character Identifications to specific metrics and raster patterns. Each Code Page and each Character Set is stored as a member in a Font Library. The name of each such member is the name of the respective Code Page or Character Set.
The Font Library may also contain members called Coded Fonts. Each Coded Font contains the name of one Code Page and one Character Set, which, in combination, define a specific FONT. The name of each Code Font member is the name of the Coded Font.
Within the Mixed Object Document Content Architecture (MO:DCA), a FONT is specified by a Map Coded Font (MCF) structure, of which there are two (2) formats, one of which is obsolete but is still supported for compatibility in some implementations. Depending on which of the MCF formats is used and which of the optional data and fields are utilized within the format used, a specific FONT can be specified by any one of the following (sets of) values:
1. Coded Font Name; or PA1 2. Code Page Name AND Character Set Name; or PA1 3. Global Resource ID (GRID), in combination with any of the following Optional Font Modifiers which may be supplied: PA1 1. Code Page Global ID (CPGID) PA1 2. Graphic Character Set Global ID (GCSGID) PA1 3. Font Global ID (FGID) PA1 4. Average Character Width (in units of 1/1440 inch)
a) Font Weight Class value--specifies character stroke thickness; PA2 b) Font Width Class value--specifies character width-to-height ratio; PA2 c) Italics Characters indicator; PA2 d) Underscored Characters indicator; PA2 e) Outline Characters indicator; PA2 f) Overstruck Characters indicator; PA2 g) Proportionally Spaced Characters indicator; PA2 h) Kerned Characters indicator. PA2 i) Character Rotation value (0, 90, 180, or 270 degrees--0 degrees assumed if not specified).
Due to the methods by which these values are specified within the MCF formats, it is possible that more than one of the above values may be specified.
The Global Resource ID (GRID) is an eight byte, hexadecimal value which is composed of four (4) two byte, hexadecimal values, as follows: